caffeine transport in single cup coffee packets

Caffeine Transport in Single CupCoffee Packets

Eric AndersonAlana Warner-Tuhy

Introduction

• Reason for Study• Experimental Parameters• Results• Conclusions• References

Justification for Study

• Warning on the back of coffee packet• How much does brewing conditions affect the

final caffeine concentration?

Experimental Parameters• Three different brewing methods– No interference– Dunk bag in water, as per directions– Continuously stir

• Other than convective conditions, all other parameters were constant

Purification and Extraction

Method 1 Results

0 1 2 3 4 5 6 7 8 9 100

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Color and Caffeine Comparison

Color Caffeine

Time (min)

Nom

alize

d Co

ncen

trati

on

Color Comparison

0 10 20 30 40 50 600.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

Color Dependence on Time

Still Dunked for 15 sec at 1 min Well Mixed

Time (min)

Abso

rban

ce

Caffeine Conc. Comparison

0 10 20 30 40 50 60 700

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Caffeine Concentration

StillDunkedStirred

Time (min)

Caffe

ine

Conc

entr

ation

(mg/

mL)

Final Caffeine ComparisonMethod Time (min) Final Concentration (mg/ml)

1 5 0.12

2 5 0.14

3 5 0.13

1 10 0.22

2 10 0.14

3 10 0.52

1 60 0.39

2 60 0.15

3 60 0.92

Results

5 Minutes– Any method will work

10 Minutes– Double the caffeine by leaving coffee undisturbed– 4 times the caffeine by continuously stirring coffee

Conclusions

• The convective component greatly affects the final caffeine concentration

• Color is not an adequate indicator of caffeine concentration

References

• Spiro, M., Lam, P., Food Chemistry, 1995 , vol. 54, p393-396.